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Ok the car ran "normal" as far as its concerned until....

I replaced my BPV which I thought was leaking with a toyota supra mk3 BPV, which is the same as ours but its metal (the stock SS one is fine but i swapped them anyways)

Than I cleared my codes the right way, just to clear them, havent had a check engine light but I wanted to make sure (the FSM way, with connecting both connectors, driving over 7mph blah blah)

Turned car off... unplugged the connectors and than drove back home....

The car has lost all its guts!! Literally... it boosts up to 10psi where I had it set at, holds boost, but the RPMs slowly climb and my foot is to the floor, has less power than geo!!

What is going on? What happened?

When you replaced the BPV did you break any of the hoses possibly? Is everything hooked up including the BPV vacuum line?

Just went and drove it again... seemed slow still until the BPV got louder, wonder if it was stuck? wonder if it was the BPV not opening? Unless this is a placebo effect...

Im going to go put the stock plastic one back on and see if anything happens.

Mattheww044 and I put a supra BPV on his car today and its fine, nothing happened bad besides the BPV noise was quieter.

ericem wrote:When you replaced the BPV did you break any of the hoses possibly? Is everything hooked up including the BPV vacuum line?

I dont think I broke anything, Ill go check.

And yeah the BPV vac line is hooked up

Where did you get these BPV? I am looking around right now i think I need another one too. When I hooked up my BPV out line I cracked the hose because it was rock hard. Now I need to order a new one

Well I went and checked and nothing is broken and the VAC gauge is still where it "normally" is

Put the stock BPV back in and its seems to be back to where it was, not as sluggish as my first post.

ericem Ive got a couple supra BPVs

I'll keep an eye on it. Anymore ideas or thoughts??

When you say it is back to where it was, you mean prior to the first swap of the BOV or is still acting up?

Will the engine free rev okay in neutral? I'm assuming no other CEL's?

Did you disconnect any wires or connectors getting to the BOV to do the swap?

Its back to where it was here "Just went and drove it again... seemed slow still until the BPV got louder, wonder if it was stuck? wonder if it was the BPV not opening? Unless this is a placebo effect..."

Both BPVs are tight, no leaks or anything.

The engine revs fine in neutral , No CELs (there wasn't any before either)

Didnt undo any wires. I checked.

Ok just to confirm, went and drove it.

-No CELs
-Revs in Neutral fine
-Idles where it usually does
-Vac is where it has been (15 inmg)
-Holds boost, no crazy drops or spikes

Its back to where it was before I made this thread asking for HELP!! Pulls hard again... Its just still irritating as Id like to know why it would do that. I think tomorrow I'm going to swap that supra BPV back on and try another and see what happens.

Quick question.....if the stock one works fine....and the supra one gives you problem, why would you change back to the supra one?

I'm running 20 psi on the stock BPV without a problem.

ive has this exact problem when mike was tuning my car, as soon as i hit a certain psi it would drop but the rpm's will still go up and the exhaust gets quiet. Myproblem was a boost leak from a broken clamp that only opened at 13 and above pounds.

Im thinking you supra bpv leaks under higher boost.

I am debating buying a brand new BPV. It is only $60. It sounds like the stock BPV is just fine.

just go with a bov, it works and cleans up the engine bay a bit. and you dont have to buy one that whistles.

Legacy777 wrote:Quick question.....if the stock one works fine....and the supra one gives you problem, why would you change back to the supra one?

I'm running 20 psi on the stock BPV without a problem.

Well Im not sure its the supra bpvs fault. So I was going to make sure. But when getting on boost the needle on my gauge flutters, ALOT and sometimes even in VAC

But today it did the same thing twice. Leaving a light it felt sluggish so I put the pedal to the floor and it wouldn't go. Same thing as before no power, RPMs slowly climb.

The second time it was gutless and than all a sudden it just threw me in the seat.

* But I just received my SSM cable and have the RevScan and am downloading EvoScan just so I can have both.

Hmm, I think I have a similar issue. I am thinking it's the BPV not sealing up properly. Like if you get into boost and the valve didn't shut wouldn't it be difficult for the valve to shut full while there is boost? It sounds like a BOV would be a better option just because of this issue with the valve not slamming shut. I haven't actually figured out a way to pressure test my BOV's with a air compressor either to see if they are indeed leaking, still doesn't replicate the car going from no boost meaning valve is open, to boost and valve closing.

when Im under boost, the needle flutters and you can hear what sounds like an air leak, almost like a turbo whistle but not because you can also hear the turbo

But thats not my major worry right now

my car has done that too. it's always a good idea to replace every vacuum line under the hood except ones with check valves. those should be inspected. As far as your needle flutter, could be a crappy gauge, could be a leak or your boost line doesnt have a plenum installed. The smallest opening running to your boost gauge should be about 1/64 of an inch. The plenum is a small metal piece with a tiny hole in it that you incorporate into the line.

As far as testing your blow off valve. Go to home depot and find a plug with a small nipple to attach the airline. the plug will go in the hose on 1 side. Find another plug for the other end of the hose. You may need a vacuum pump to open and close your bypass valve and two tees with two gauges, one before the bpv and one for after. It would be a good idea to have a regulator on the compressor so your not putting out 100lbs . make sure your clamps are tight and your safety glasses are on and slowly fill. if the pressure doesnt equalize on both side your sealed. then you can pull vacuum to make sure your bpv opens quickly.

there's probably easier ways, but when im high i get deep into thought

I was also thinking it was my gauge. The vac line running to the gauge is quit big and Ive read that it can cause flutter, I plan on switching the vac line to smaller inside diameter line and see if that helps at all. I have a plenum or whatever (Greddy calls it an "air filter" ) from my EBC I was running. I'll put that inline with smaller vac line and see if that helps at all with flutter.

your line should be a white nylon line with a very small diameter.

yeah mines not. Im getting a new boost gauge today to match my others anyways and it comes with the nylon line.

But that doesnt solve my bigger issue tho. But I now have the ssm cable now and plan on data logging and such saturday as well as some maintenance

not to be off topic, but RJ, your car runs fine with an atmosphere BOV? i put the stock sti one on and it sounds sweet, but my car doesn't like it at all. I can't risk my car's "health" for a cool noise... i wonder why it would run crappy on mine but fine on yours? I think part of the reason is that it is a BPV, but ran as a BOV, i've heard your not "supposed to" run BPV's as BOV's.

my guess is the sti one is open at idle and sucking in unmeasured air. most aftermarket bov's are closed at idle. I tried what your talking about with my stock one and no good came out from that.

i can stall my car with the bov if i tap the gas in nuetral cause my bov will still be open but other than that i have no problems. not sure how it would work on a stick?

What would happen if I didn't have a vacuum line on my BPV? and plug the line?

Im pretty sure that line controls when it opens and closes

hmmm... i will see if any of my buddies have a spare BOV lying around to see what it sounds/runs like. Like you said, it cleans up the engine bay tremendously. Which BOV are you running?